链表的插入排序

struct node heada, headb;
link t, u, x, a = &heada, b;

for (i = 0, t = a; i < N; i++)
  {
    t->next = malloc(sizeof *t);
    t = t->next; t->next = NULL;
    t->item = rand() % 1000;
  }

b = &headb; b->next = NULL;
for (t = a->next; t != NULL; t = u)
  {
    u = t->next;
    for (x = b; x->next != NULL; x = x->next)
      if (x->next->item > t->item) break;
    t->next = x->next; x->next = t;
  }